Floor-covering material and process of making same



FLOOR COVERING MATERIAL AND PROCESS OF MAKING SAME Filed Nev. 23, 1926 N\TR.OC.ELLULOSE ETC. TRERD.

wATEnmboFan PAPER SUPPORT,

CARLETON ELUS Patented Dec. 9, 1930 UNITED STATES PATENT. OFFICE A CORPORATION OF NEW JERSEY FLOOR-COVERING MATERIAL AND PROCESS OF MAKING SAME Application filed November 23, 1926. Serial No. 150,387.

This invention relates to floor coverings and relates in particular to floor coverings containing cellulose plastics, as for example, cellulose nitrate or acetate,.and also the various ethers of cellulose. The invention will be illustrated by compositions in which nitrocellulose is an essential component.

The drawing shows a cross section through a floor covering made in accordance with the present invention.

Floor coverings of the linoleum type, or those made from a felt base saturated with asphalt, the upper surface of which is printed in-various designs, have certain disadvantages which need not be enumerated .here. These products have as an essential constituent of the surfacing material a boiled oil or drying oil component. In the present invent-ion it is an object to employ as a binder or carrier of pigment a nitrocellulose plastic in lieu of the boiled oil material.

Floor coverings of the so-called rug type made from linoleum composition or saturated felt base,.should have the property when rolled out on the floor, of flattening and not show any tendency at the corners to curl. They should be of a character which permits rolling and shipping without cracking. Nitrocellulose, especially that type which forms solutions of high viscosity forms a tough finish on the surface of a floor covering, but when'used as the sole component of such surface is too hard and slippery and also causes the floor covering to curl. If plasticizers are added, in many cases these tend to lose their efficacy after a time.

Rugs surfaced in this manner with nitrocellulose also have the disadvantage of being very readily inflammable.

Nitrocellulose varies greatly in its characteristics of viscosity and working qualities, and in making floor coverings employing pyroxylin 1 may use nitrocellulose of high or low viscosity, or mixtures of nitrocellulose of high and low viscosity.

In preparing a nitrocellulose plastic containing a considerable amount of tiller such as ground wood, cork, and the like, the high viscosity nitrocellulose enables a better mixing and kneading eticct to be secured, but it does not supply a large proportion of binder. The high viscosity nitrocellulose may be regarded as simply distended in the solvent which may be employed, giving the appearance of body or substance. but as-a matter of fact, furnishing very littlereal binding quality. The low viscosity nitrocellulose a re weaker, but can be used in much higher con centrations, and therefore by employing the high viscosity nitrocellulose to obtain kneadability and strength, andlthc low viscosity nitrocellulose to yield greater nitrocellulose content, I propose to obtain new and improved results in the commercial production of floor coverings.

:lVith the nitrocellulose I may employ a resinous substance if desired, such substance giving-additional body and in the case of certain synthetic resins which I shall later describe concerning what may be termed a protective influence 011 the nitrocellulose and improving its resistance to alkali. Since linoleuln and other floor coverings are frequently subjected to the action of soap and water, and since nitrocellulose by itself is quite easily affected by alkali, the addition of a protective resin is of considerable importance 111 some cases.

The viscosity and strength ot' nitroccllu lose is very quickly altered by contact with alkali. For example, high viscosity pyroXylin such as celluloid cotton may be transformed into a low viscosity product by treatment in solution with a small amount of anr monia. On standing for a few hours in contact withthc ammonia, the viscosity instead of being represented by the viscosity designation or 75 seconds, may be, for example, reduced to a low viscosity cotton of the second type. Methods of making the low viscosity cotton do not form a part of the present invention, but I may use such pyroxylin, whether obtained by chemical methods, by heat treatment of nitrocellulose, by pre-treatment of the cellulose fibre, or by special methods of nitration. In any ereut. the sensit-iveness of nitrocellulose to alkali. such as would be present in soap and water used for washing the surface of a nitroccllulose floor coverim is such that protective means are generally required, and the synthetic resins referred to above may be employed for this purpose.

A series of resins having a protective influence on nitrocellulose in lacquers, and the like, are set forth in several of my copending applications, such for example as Serial No. 142,532 and Serial No. 144,647. In the latter case I have stated that by the incorporation with a mixture of or solution of nitrocellulose and such synthetic resins of various fillers, as for example, ground cork, wood flour, and the like, floor coverings or linoleum substitutes may be made. also stated that floor coverings made from such a duplex binder may be printed or,

inlaid in colors contained in a composition comprising said binders.

A series of such protective resins set forth in Serial No. 142,532 are the following, proportions parts by weight:

(A) Linseed phtlzaZ/e glyceride resin Glycerol 94 Phthalic anhydride 160 Fatty acids of linseed oil 80 Heated to 250 C. for about 2 hours. Light brown resin, acid number 20.2 com patible with nitrocellulose and soluble in butyl acetate.

(B) Cottonseed phthalie glyeeride resin Glycerol 94 Phthalic anhydride 160 Fatty acids of linseed oil W 80 Heated to 240 C. about 4 hours. Light brown resin, acid number 22.4 compatible with'nitrocellulose and soluble in butyl ace tate.

(0) Blown rapeseed pat/MUG g/y cer/We resin I Glycerol 94 Phthalic anhydride 160 Fatty acids of blown rapeseed oil 80 Heated to 260 C. for'2 hours. Dark brown tough resin, acid number 20.6 blends well with nitrocellulose.

(D) Sag a bean plzthalic glg eeride resin Glycerol 94 Phthalic anhydride 160 Fatty acids of soya bean oil 8O Heated for 1 hours to maximum ternperature of 265 C. Brown, transparent resin. melting point 71 (1., acid number 17.2. Soluble in butyl acetate and blends well with nitrocellulose.

(E) 130222050 platimlz'c'glycerz'de Benzoic acid 98 Phthalic anhydride 118 Glycerol -11 94 Heated to 230 C. within A, hour. vac- It is uum of 28 inches was then applied and the temperature slowly raised to 290 C. Product is a pale slightly tacky resin of acid number 16.6, soluble in ethyl and butyl acetates and compatible with nitrocellulose.

(F) Benzoic nitro-benzoic phthalz'c gig ceride resin Glycerol 94 Phthalic anhydride 118 Benzoic acid containing about 10 percent p-nitro-benzoic acid 98 resin, acid number 18.8.

(G) Castor-oil plzthalic gig col res/n Mixture of about equal parts ethylene and propylene glycols 104 lhthalic anhydride 160 Castor oil 80 Heated to 240 C. in 1 .hours. Pale,

soft, sticky resin, acid number 15.3. Soluble in butyl acetate and compatible with nitro-v cellulose.

- (H) Gastor oil pht/zalz'o glyceride resin Glycerol 94 Phthalic anhydride 160 Castor oil 80 Heated to about 235 C. gave pale resin, acid number 12, soluble in butyl acetate and compatible with nitrocellulose. This resin differs in several respectsfrom those resins described above made with the acid of the free fatty acids of vegetable oils (viz A, B, C and D).

Heated to 280 C. in 2 hours. Dark colored Resins of this character incorporated with nitrocellulose of high or low viscosity,- or mixtures of these, and with the further addition of a plasticizer, in some cases, may be admixed in an appropriate solvent with fillers of quite varied character, including those above mentioned, and various fibrous sub stances, such as wood pulp, sawdust,.begasse,i

employ nitrated alpha cellulose, or nitrated wood flour, or similar nitration products derived from cheap materials which are not necessarily clean or pure cellulose. lVhile such procedure would not be appropriate in the manufacture of smokeless powder as requisite stability probably could not be maintained, the same restrictions are not imposed in the case of a floor covering because the latter may contain a large proportion of whiting or zinc oxide as antacid pigments.

()n the other hand I prefer not to employ a pigment such as titanox without an antacid pigment. owing to possible deterioration of the surface. The invention therefore embraces the employment of cheap nitrocellulose ol a lower grade than would be customarily employed in making other products such as smokeless powder or various plastics in which the risk of using such low grade nitration products without the ability to incorporate the necessary antacid substances would be too great. I

The employment of such nitrocellulose materials aids in making a product of low cost without tending to involve increased; fire hazard.

The high degree of inflammability of nitrocellulose may be better reduced by the incorporation of a synthetic resin and may be furthcr reduced by the addition of such substances as triphenyl phosphate or tricresyl phosphate. These act as plasticizers and tend to increase theflexibility and yielding qualities of the nitrocellulose.

By incorporation of synthetic resins as aforesaid and a plast-icizer such as tricresyl phosphate, not only is the inflammability containing water of. hydration.

greatly reduced, but furthermore a floor covering may be produced which does not curl at the corners. This is of the utmost importance as a floor rug which lifts from the floor at the corners, or which buckles seriously is highly objectionable. The synthetic resin, therefore, in addition to its protective effect on the nitrocellulose against alkalies, may be regarded as a flattening agent.

Additional fire resistance may be secured by the incorporation of fillers having water of hydration, for example, calcium sulphate Such a. filler has a considerably greater suppressing influence on inflammability than substances such as ground cork or Wood flour.

A tiller material, therefore, may advan-- tageously consist of: y

(1) An antacid pigment such as zinc oxide.

(2) A combustion resisting pigment such as hydrated calcium sulphate.

(3) An inert filler such as ground cork or ground wood.

A filler mixture of this character may be incorporated with a solution of nitrocellulose, synthetic resin and plasticizer, as ind-i- I cated above, by kneading in a powerful ma chine, as for example, a WVerner 'Pfleiderer mixer. The composition may then be sheeted onto a paper support: For example, this may be carried out on milling rolls or dif ferential rolls by running the sheet of paper through the rolls while the la-tterare kept applications.

of the other, a differential effect results which gives a smoother and more polished surface to the sheeted material than 18 obtalned with rolls running at'the same speed.

Finally, should it be desired to give to the surface of this sheeted material a high finish or gloss, the sheet may be'coated with a nitrocellulose synthetic resin solution such as those described in various of my copending See for example, Serial No. 142,532 and Serial No. 144,647 Furthermore, this final coat, if desired, may have pigments or dyes added. If the clear solution only is applied, the color of the sheeted.

material beneath is enhanced and a surface more or less glossy, depending upon the amount of the resin present, results.

In the present invention, I employ a sheet or strip of paper as a tread sheeting support.

The paper used need not be stiff and heavy as in the preferred form of the invention I do not rely on the paper for cushioning effect, using it merely as a moving surface on which to deposit a layer of soft putty-like material constituting the undried tread composition. Hence, a thin, even somewhat flimsy paper may be employed, just strong enough to bear the load of tread composition.

Papers of the krafttype are serviceable, be-

ing strong and flexible. A supply of such paper in roll form of the requisite width may be fed from a spindle to a pair of sheeting rolls. Onto these the putty-like tread.

composition is supplied continuously, preferably to one side of the paper only. As paper and tread composition pass through the sheeting rolls the composition is pressed and flattened into contact with the paper and a smooth layer of the composition of sa v or of an inch in thickness is thus formed.

From the sheeting rolls the paper with its single layer of tread composition is led through a drier where solvent removed and the previously weak tread becomes strong and tough. The paper and tread now make a sturdy material which may be used as such asfloor covering. The surface of the tread may be given a better finish by hot calendering the dry or nearly dry composition. Diiferentially-speeded sheeting rolls assist in giving a smooth tread finish which may be further enhanced by calendermg.

A preferred form of the invention, however, is that of applying to the paper two, or even a greater number of tread layers. Thus two layers may be applied to the same side. of the sheet to givea double thickness of tread, or the layers may be applied to 0pposite sides of the sheet so as to provide a redrying intervening'before the second tread versible tread. These opposed layers may be of the same color or of different colors.

and as a result a. smoother finish may be better obtained by superposing tread layers. More than two layers may be used in'some cases.

When opposed treads are desired the tread composition may be fed to both sides of the paper passing through the sheeting rolls so that a dual tread is formed in one operation or one tread may be applied at a time,

is sheeted on.

Still heavier floor covering is made by adding-further tread layers as desired.

Drying may take place in a heated drying chamber fitted with a solvent recovery system. I In some cases no solvent is employed, the tread composition being kept in a soft puttylike condition by using heated rolls. (Hol low rolls, steam-heated).

A dual or duplex rug made in this manner possesses the especial utility of being reversible, providing a fresh wearing surface or tread merely by turning the rug over. The same holds true for long strips or runners for use in the halls of public buildings, hospitals, and the like.

The paper employed for sheeting purposes may carry fireproofing salts, colors, agents conferring flexibility and the like. Low cost, however, is usually an important consideration and preferably I employ a cheap grade of paper, for example, one made from a mixture of sulphite pulp and ground wood. To achieve water resistance without going to the expense of loading the paper heavily with waterproofing agents, e. g., asphalt orpitch, and furthermore, to keep the paper layer light in color when tread material of amount of a wax emulsion.

a light shadeis to be applied, I may add to the paper pulp in the beater engine a small Thus with the aid of only 1 per cent of parafiin wax on the weight of the finished paper I obtain important waterproofing results without producing a greasy or oily surface to which the tread composition would have poor adherence.

The method of making such paper forms no part of the present invention. (Some of the processes available for thepurpose are.

tic mass.

represented by U. S. Patents 1,607,517, 1,607,518, 1,607,519 and 1,607,552 all of November 16, 1926).

The use ofwaxed paper to which nitrocellulose tread coatings are adherent yielding suitable fioor coverings does, however,

form a part of the presentinvention.

Thus I have employed five grades of paper made by adding wax emulsion to paper pulp in the beater, namely:

(A) Approximately 3 per cent paraffin wax. No rosin size. Beaten 1 hours.

(B) Wax 1 per cent. Rosin 1 per cent. Beaten 3 hours.

(C) lVax 1 per cent. Beaten 2% hours.

(D) WVaX 1 per cent. Beaten 1 hour.

Rosin only, 2-1.2 per cent. Beaten 3 hours.

This paper material was not smooth calendered, but was made with a slightly uneven surface assisting in giving the tread composition a better attachment.

The tread layers showed excellent adher- Rosin 2 per cell].

'ence to the paper which had been waterproofed with emulsified w'ax despite the repellent nature of wax on nitrocellulose.

The floor covering. illustrated in the drawing shows in crossscction the waterproof paper support 1 carrying a nitrocellulose composition tread or other tread made in accordance with disclosure herein.

Ema/mph]. Use of saturated felt basc. Rag paper or felt saturated with asphaltic material was used as the support. The thickness of the saturated felt was 1.6 mm.

140 parts by weight of celluloid nitrocellulose containing 40 parts alcohol, was mixed with 133 parts dibutyl phthalate, parts acetone, 60 parts benzol, 2.5 parts ceresine wax (previously dissolved in benzol)'150 parts ground cork, parts whiting, 75 parts green pigment. This mixture, owing to the presence of the wax, did not dry quickly and could be worked with freely without hardening. It was sheeted on the felt base in situ, that is, applied directly thereto by running the felt base through milling rolls on which was situated a quantity of the plas- The latter was of the consistency of a stiff putty and sheeted readily on the felt base and the composite material was dried at 40 C. for one hour, then the opposite side was sheeted in situ in a similar manner and in this way a duplex or reversible floor rug was secured of about 3 mm. thickness.

Example .2.Paper of the quality designated above as A was sheeted on one side with a tread'compos'ition similar to that used in Example 1.

On the opposite side a mixture of brown Rosin 3 per cent.

llu

color was applied. This was made from 50 'a waxed palwr-bottom.

parts nitrocellulose one-half second viscosity, 133 parts tricresyl phosphate, 200 parts secondary butyl acetate, 150 parts ground cork, 7 5 parts whiting. In this manner a reversible floor rug was obtained of a fine green color on one side and a soft brown on the other side. The paper employed was about 5 mm. thick-' ness and the resulting floor covering was slightly over 2 nnn. in thickness.

Elva/M7170 ).l7aper of the grade B mm. in thickness was shected on one side only with a composition-of the character given in Example 1. This produced a greentread and The thickness was 1.35 mm.

Emn mplc 4.Paper of grade C 'was sheeted with green composition of the formula used in Example 1. the tread mixture was applied to one side only. .The floor covering had a thickness of 1.9 mm.

Elm/mp7s 5.The same green composition was morevheavily sheeted on paper of grade E. The thickness of the. latter was 0.5 mm., and the thickness of the R sulting floor covering was 2.25 mm. I

[211119117770 6.laper of the character given above as grade D and having a thickness of 0.5 mm. was sheeted on one side with green composition of the type used in Example 1 and after drying the opposite side was sheeted with composition of brown color. described under Example 2. The resulting floor covering was 2.14 mm. in thickness. Emmnple '7. I.nstead of using a waxed paper core or inner layer carrying a tread on either side I may proceed as follows:

Manila paper 0.3 mm. thickness has applied v to each side a tread composition same as used in Example 1. The thickness of the rug or floor covering was 2.5 mm. in the product made in this manner..

E ram-pie 8.100 parts 40 seconds nitrocellulose. partscottonseed fatty acid phthalic glyceride resin. 163 parts tricresylphosphate, 100 parts secondary butyl acetate. 175 parts ground cork, 100 parts whiting. This was ap plied to manila paper 0.3 mm. in thickness, sheeting on one side only to give a brown tread. The finished product was 1.03 mm. in thickness.

lib-ample ).To the composition employed as a plastic in Example 8, 25 parts of green pigment was added and this mixture was sheeted on the opposite side of a portion of the floor covering obtained in'accordance with Example 8. A duplex rug resulted, the tread on one side being brown and on the other side green.

What I claim is 1. The process which comprises sheeting onto a flexible strong paper support a tread composition comprising nitrocellulose, a synthetic resin, plasticizer, fibrous filler and Wax.

2. The process of making floor coverings which comprises sheeting onto wax-containhacking carrying a cushioning tread of waxj containing nitrocellulose on at least one face of said backing. v

' 6. A reversible floor covering comprising a waxed paper core carrying on at least one face thereof a nitrocellulose containing layer acting as a cushioning tread.

7. ,A reversible floor covering comprising a paper core water-proofed with emulsified wax, said core carrying on each face thereof a cushioning tread containing nitrocellulose.

8. A floor covering comprising a waxed paper core :arrymg a cushioning tread contain-ing nitrocellulose and a synthetic resin compatible therewith.

9. An article of manufacture comprising a waterproofed paper core carrying a cushioning tread containing nitrocellulose, a synthetic resin compatible therewith, a plasticizer and pigment.

CARLETO N- ELLIS. 

